From: Greg KH <greg@kroah.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
LSM <linux-security-module@vger.kernel.org>,
James Morris <jmorris@namei.org>,
Kees Cook <kees.cook@canonical.com>,
containers@lists.linux-foundation.org,
kernel list <linux-kernel@vger.kernel.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Michael Kerrisk <michael.kerrisk@gmail.com>
Subject: Re: [RFC 1/5] user namespaces: Add a user_namespace as creator/owner of uts_namespace
Date: Sat, 18 Dec 2010 09:56:51 -0800 [thread overview]
Message-ID: <20101218175651.GA7453@kroah.com> (raw)
In-Reply-To: <m1vd2rlhez.fsf@fess.ebiederm.org>
On Fri, Dec 17, 2010 at 10:32:52PM -0800, Eric W. Biederman wrote:
> Greg KH <greg@kroah.com> writes:
>
> > On Fri, Dec 17, 2010 at 12:40:11PM -0800, Eric W. Biederman wrote:
> >> Greg KH <greg@kroah.com> writes:
> >>
> >> >> There are also major benefits to have the version of something that is
> >> >> never freed never going away, because it means you can just reference it
> >> >> in code. So while I would be happy to say this is special don't use a
> >> >> kref and roll the reference counting logic by hand, we aren't
> >> >> dynamically allocating init_uts_ns any time soon.
> >> >
> >> > Why have a reference count at all if it's not needed or used here?
> >>
> >> We have to reference count every other uts namespace.
> >
> > Ok, that makes sense, then also please dynamically create this one, do
> > not create a static kref.
>
> Nope. It's a bad idea. It messes up the kernel bootstrap if you do
> that, and it makes this one structure different from every other
> structure init_task uses.
{sigh}
Ok, but I really don't like this use.
Also, don't go messing with that ATOMIC_INIT() to be a higher value, as
this patch series did, as that really implies that it is being used
incorrectly, right?
thanks,
greg k-h
next prev parent reply other threads:[~2010-12-18 17:55 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-17 15:22 [RFC 0/5] user namespaces: start clamping down Serge E. Hallyn
2010-12-17 15:24 ` [RFC 1/5] user namespaces: Add a user_namespace as creator/owner of uts_namespace Serge E. Hallyn
2010-12-17 15:25 ` [RFC 2/5] user namespaces: make capabilities relative to the user namespace Serge E. Hallyn
2010-12-17 15:26 ` [RFC 3/5] user namespaces: allow sethostname in a container Serge E. Hallyn
2010-12-17 15:26 ` [RFC 4/5] user namespaces: allow killing tasks in your own or child userns Serge E. Hallyn
2010-12-17 15:27 ` [RFC 5/5] user namespaces: Allow ptrace from non-init user namespaces Serge E. Hallyn
2010-12-17 19:45 ` Eric W. Biederman
2010-12-17 20:04 ` Serge Hallyn
2011-01-01 4:47 ` Serge E. Hallyn
2010-12-17 19:31 ` [RFC 4/5] user namespaces: allow killing tasks in your own or child userns Eric W. Biederman
2010-12-17 20:09 ` Serge E. Hallyn
2010-12-17 20:17 ` Eric W. Biederman
2010-12-17 20:22 ` Serge E. Hallyn
2011-01-01 4:45 ` Serge E. Hallyn
2011-01-01 23:10 ` Eric W. Biederman
2011-01-02 14:39 ` Serge E. Hallyn
2010-12-17 15:56 ` [RFC 1/5] user namespaces: Add a user_namespace as creator/owner of uts_namespace Alexey Dobriyan
2010-12-17 16:00 ` Alexey Dobriyan
2010-12-17 16:17 ` Serge Hallyn
2010-12-17 16:12 ` Serge Hallyn
2010-12-17 17:31 ` Greg KH
2010-12-17 19:26 ` Eric W. Biederman
2010-12-17 19:58 ` Greg KH
2010-12-17 20:40 ` Eric W. Biederman
2010-12-17 23:15 ` Greg KH
2010-12-18 6:32 ` Eric W. Biederman
2010-12-18 17:56 ` Greg KH [this message]
2010-12-17 19:46 ` Serge Hallyn
2010-12-17 19:57 ` Greg KH
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